Hydrostatic torque converter and torque amplifier

ABSTRACT

An example includes a hydraulically controllable coupling to couple a rotating input and to an output to rotate, or to decouple the input and the output, with coupling and decoupling modes selected by switching a hydraulic device such as a vane pump between a pumping mode and a mode in which it does not pump. In an example, the system cooperates with a transmission to increase the number of possible gear ratios in some examples.

PRIORITY CLAIMS AND RELATED APPLICATIONS

The present subject matter claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/263,295, filed Nov. 20, 2009, and to U.S. Provisional Patent Application Ser. No. 61/263,304, filed Nov. 20, 2009, which applications are incorporated herein by reference in their entirety.

The present application is related to international application no. PCT/AU2007/000772, publication no. WO/2007/140514, entitled, “Vane Pump for Pumping Hydraulic Fluid,” filed Jun. 1, 2007; international application no. PCT/AU2006/000623, publication no. WO/2006/119574, entitled, “Improved Vane Pump,” filed May 12, 2006; and international application no. PCT/AU2004/00951, publication no. WO/2005/005782, entitled, “A Hydraulic Machine,” filed Jul. 15, 2004, the entire specification of each of which is incorporated herein by reference in their entirety.

TECHNICAL FIELD

This document relates generally to rotary couplings, and more particularly, to a hydrostatic torque converter.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate generally, by way of example, various embodiments discussed in the present document. The drawings are for illustrative purposes only and may not be to scale.

FIG. 1A is a perspective view of a hydrostatic torque converter, according to some examples.

FIG. 1B is a cross section taken along line 1B-1B in FIG. 1A.

FIG. 2 is a cross section view of a hydrostatic torque converter, according to some examples.

FIG. 3A is a top view of a hydrostatic torque converter, according to some embodiments.

FIG. 3B is a front view of the hydrostatic torque converter of FIG. 3A, according to some embodiments.

FIG. 3C is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3C-3C.

FIG. 3D is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3C-3C.

FIG. 3E is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3E-3E.

FIG. 3F is a partial cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3F-3F.

FIG. 3G is a partial cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3G-3G.

FIG. 4A is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 4A-4A.

FIG. 4B is a cross section of the hydrostatic torque converter of FIG.

3A taken along the line 4B-4B.

FIG. 5 is a partial cross section view of a balance piston of the couple of FIG. 3A taken along the line 5-5.

FIG. 6 is perspective view of a portion of an input and output of the couple of FIG. 2.

FIG. 7 is a schematic of a hydraulic couple including a cross-section view of a rotating group including pins to extend and retract vanes, according to some examples.

FIG. 8A is a perspective view of a hydraulic couple with a geared body, according to some examples.

FIG. 8B is a cross section taken along line 8B-8B in FIG. 8A.

FIG. 9 is a table showing experimental figures related to a first operating condition.

FIG. 10 is a table showing experimental figures related to a first operating condition.

FIG. 11 is a table showing experimental figures related to a first operating condition.

FIG. 12 illustrates a torque amplifier in a couple disengaged of operation, according to some embodiments.

FIG. 13 illustrates a torque amplifier in an driving mode of operation, according to some embodiments.

FIG. 14 illustrates a torque amplifier in a braking mode of operation, according to some embodiments.

FIG. 15 illustrates a torque amplifier in a regenerative braking mode of operation, according to some embodiments.

FIG. 16 illustrates a torque amplifier in a first mode of operation, according to some embodiments.

FIG. 17 illustrates a vehicle including a torque amplifier, according to some examples.

FIG. 18 illustrates a load ultimately driven by an electrical motor, according to some embodiments.

FIG. 19A is a perspective view of a vane including a roller tip, according to an example.

FIG. 19B is a bottom view of FIG. 19A.

FIG. 19C is a top view of FIG. 19A.

FIG. 19D is a front view of FIG. 19A.

FIG. 19E is a side view of FIG. 19A.

FIG. 19F is a perspective view of FIG. 19B, cross-sectioned at line 19F-19F.

FIG. 19G is a bottom view of FIG. 19F.

DETAILED DESCRIPTION

This describes examples in which a couple transmits rotary motion from an input of the couple to an output of the couple. In various examples, a couple is hydraulically controlled, such as with a pilot signal, to control fixing a torque input of the couple and a torque output of the couple such that a rotational torque on the input of the couple is transmitted to the output of the couple. In response to a further pilot signal the couple is controlled to unfix the input of the couple and the output of the couple to allow the input of the couple and the output of the couple to rotate independently.

In various examples, a couple includes a hydraulic pump with a rotating group coupled to an input of the couple, and with a rotating group housing coupled to an output of the couple. In various examples, by rotating the rotating group in the rotating group housing, the pump will pump oil once a threshold torque between the input of the couple and the output of the couple is reached. Until the threshold torque is reached, the pump transmits torque from the input of the couple to the output of the couple without pumping oil, and accordingly is highly efficient. In various examples, through pumping oil, a couple can be overloaded without damage. In some examples, the pumped oil escapes over a relief valve. In some examples, the maximum amount of torque transferred is adjustable by adjusting the relief valve.

The couple is useful in a variety of applications, such as to drive a fan to cool a machine, to transmit torque in a vehicle, to control torque transmission in an industrial machine, or to accomplish other acts in which an output torque is to be selectively deactivated from an input torque. The couple improves upon prior designs such as clutches and torque converters by using a hydraulic device that can efficiently transmit high torques. Some examples use vane pumps that can be economically manufactured.

The couple is efficient because there are few or no efficiency penalties when the couple engages the input of the couple and the output of the couple to spin together. When spinning together, there are few or no hydraulic efficiency losses such as those losses in a torque converter that cannot lock. The couple further improves efficiency by enabling the selective disengagement of rotating machines. For example, a conventional power output of a machine, such as a power take-off, would normally spin whatever was hooked to it in concert with the rotation of the power take-off. The couple improves upon this by enabling for the disengagement of that which is coupled to the power output, saving energy. In some embodiments, the couple uses a closed system requiring only a pilot signal and an optional drain to tank or reservoir. Some examples include an adjustable relief valve to control maximum torque transmitted.

This document presents examples of a multi-mode torque multiplying system. The system is to couple to a torque source such as an engine or electric motor to output torque such as to a transmission or another powertrain component. The pumps are controlled such as with a valve to selectively transmit power or absorb power for future use. The system improves upon prior drive designs by providing a hydraulically controllable coupling between the torque source and a load to be driven with torque. Unlike other hybrid hydraulic approaches, in certain instances the hydraulically controllable couple provides an improved configuration in which the system can reduce or eliminate hydraulic propulsion, and its associated inefficiencies, to improve performance of a vehicle or industrial drive system.

FIG. 1A is a perspective view of a hydrostatic torque converter, according to some examples. FIG. 1B is a cross section taken along line 1B-1B in FIG. 1A. Various embodiments include an input shaft 102 coupled to rotate a body 104 defining a chamber 105. The body 104, in some examples, is a vane pump or vane motor housing or a portion thereof, such as a ring. In further examples, the body 104 is housing of another kind of pump, such as a piston pump or motor or a gear pump or motor. Rotating the body 104 can rotate the rotating group 105 and in turn rotate the output 103. Such rotating occurs in some examples when the couple 100 is in mode in which the rotating group 105 works fluid such as hydraulic fluid between the rotating group 105 and the body 104.

In the operational mode in which rotation of the body 104 works fluid between the body 104 and the rotating group 105, pressures between the two are maintained at a high level, resisting rotational movement between the two, thereby imparting high torque to the output 103. To release the rotating group 105 from a couple with the body 104 to allow independent rotation of the input 102 and the output 103, the rotating group 105 and the body 104 are switched to a mode in which the rotating group 105 does not work fluid, thereby allowing the rotating group 105 to rotate and thus the output 103 to rotate.

In various embodiments, the rotating group 105 is in fluid communication with an inlet 112. Some examples position portions of the couple 100 in fluid communication with an optional drain 114. A fluid signal from the inlet 112 is to switch the couple 100 from a first mode, in which the input 102 can rotate with respect to the output 103, and a second mode, in which they are coupled due to the resistance of the rotating group 105 to pump fluid by working fluid against the body 104. In various embodiments, working surfaces 106 of the rotating group 105 are either deployed in the first mode or retracted in the second mode. In a deployed mode, the working surface 106 works fluid to rotate the body 104. In a retracted mode, the working surfaces 106 are retracted and do little or no work to fluid, thereby allowing the body 104 to move with respect to the rotating group 105. Retainers 116 are used to either deploy or retract the working surfaces 106. In some embodiments, the first mode deploys vanes of a vane pump, and in the second mode, retracts them.

Various examples include an optional remote pressure control 120. In some examples, the remote pressure control is coupled to one side of a balance piston, with pump output in fluid communication with the opposite side of the balance piston. The balance piston is to control whether the pump can pump oil. For example, if the remote pressure control is set to a pressure, the balance piston allows coupling discharge pressure to rise until the coupling discharge pressure is higher than the pressure, moving the balance piston to overcome the remote pressure control pressure. As the balance piston moves, it enables the coupling discharge to drain, such as to tank. In such a manner, the maximum torque transmitted is remotely controllable via the remote pressure control signal 120. In some examples, the remote pressure control is used in addition to a primary relief valve that allows oil to pump in any case where a torque differential between a couple input 102 and a couple output 103 exceeds a predetermined threshold.

In some examples, the inlet 112, drain 114 and remote pressure control 120 are coupled to a coupling housing 118, but the present subject matter is not so limited. In some of these examples, various seals are used to guide the inlet 112 signal to the appropriate portion of the couple 100. Additional seals guide any excess fluid out the drain 114. Further seals guide the remote pressure control to a valve such as a balance piston. The drain 114 is optional and some examples control which mode the couple 100 operates in without use of an drain 114. In some examples, the housing 118 is omitted in favor of running the remaining portions of the couple 100 in an oil bath.

In additional embodiments, the inlet 112 is coupled to one of the input 102 or the output 103. In some examples, the drain 114 is coupled to the other of the input 102 or the output 103. Some examples couple the inlet 112 and the drain 114 both to one of the input 102 and the output 103. It should be noted that the assignment of the body 104 as the input is not limiting, and the body could alternatively be coupled to an output.

The present subject matter includes embodiments in which working surfaces of other pumps are held in a retracted position. For example, a retainer retains a piston of a piston pump to prevent the piston from moving in a cylinder bore to work a fluid.

FIG. 2 is a cross section view of a hydrostatic torque converter, according to some examples. In this embodiment, an input shaft 202 is coupled to a rotating group 205 to turn the rotating group when the couple 200 is in mode in which the rotating group 205 works fluid such as hydraulic fluid between the rotating group 205 and the body 204. Various embodiments include an output shaft 202 coupled to rotate a body 204 defining a chamber 205. The body 204, in some examples, is a vane pump or vane motor housing. In further examples, the body 204 is housing of another pump, such as a piston pump or motor or a gear pump or motor.

In an operational mode in which rotation of the rotating group 205 works fluid between the body 204 and the rotating group 205, pressures between the two are maintained at a high level, resisting rotational movement between the two, thereby imparting high torque to the output 203. To release the rotating group 205 from a couple with the body 204 to allow independent rotation of the output 202 and the input 203, the rotating group 205 and the body 204 are switched to a mode in which the rotating group 205 does not work fluid, thereby allowing the rotating group 205 to rotate and thus the input 203 to rotate.

In various embodiments, the rotating group 205 is in fluid communication with an inlet 212. A fluid signal from the inlet 212 is to switch the couple 200 from a first mode, in which the output 202 can rotate with respect to the input 203, and a second mode, in which they are coupled due to the resistance of the rotating group 205 to pump fluid by working fluid against the body 204. In various embodiments, working surfaces 206 of the rotating group 205 are either deployed in the first mode or retracted in the second mode. In a deployed mode, the working surface 206 works fluid to rotate the body 204. In a retracted mode, the working surfaces 206 are retracted and do little or no work to fluid, thereby allowing the body 204 to move with respect to the rotating group 205. Retainers 216 are used to either deploy or retract the working surfaces 206. In some embodiments, the first mode deploys vanes of a vane pump, and in the second mode, retracts them. In some examples, inertial forces draw the working surface 206 out to meet the body 204, such as when the input 202 is spinning rapidly.

Various examples include an optional remote pressure control 220. In some examples, the remote pressure control is coupled to one side of a balance piston, with pump output in fluid communication with the opposite side of the balance piston. The balance piston is to control whether the pump can pump oil. For example, if the remote pressure control is set to a pressure, the balance piston allows coupling discharge pressure to rise until the coupling discharge pressure is higher than the pressure, moving the balance piston to overcome the remote pressure control pressure. As the balance piston moves, it enables the coupling discharge to drain, such as to tank. In such a manner, the maximum torque transmitted is remotely controllable via the remote pressure control signal 220. In some examples, the remote pressure control is used in addition to a primary relief valve that allows oil to pump in any case where a torque differential between a couple input 202 and a couple output 203 exceeds a predetermined threshold.

In some examples, the inlet 208 is coupled to a coupling housing 218, but the present subject matter is not so limited. In these embodiments, various seals are used to guide the inlet 212 signal to the appropriate portion of the couple 200. In some examples, the housing 218 is omitted in favor of running the remaining portions of the couple 200 in an oil bath. In additional embodiments, the inlet 112 is coupled to one of the output shaft 202 or the input shaft 203.

FIG. 3A is a top view of a hydrostatic torque converter, according to some embodiments. FIG. 3B is a front view of the hydrostatic torque converter of FIG. 3A, according to some embodiments. FIG. 3C is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3C-3C. FIG. 3D is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3C-3C. FIG. 3E is a cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3E-3E. FIG. 3F is a partial cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3F-3F. FIG. 3G is a partial cross section of the hydrostatic torque converter of FIG. 3A taken along the line 3G-3G. This detailed depiction is of one embodiment, and other embodiments are possible, including embodiments in which another style of pump is used, such as a piston pump or a gear pump.

Various embodiments include an input 10 coupled to couple to a torque source. An output 11 is to couple to a powertrain. Examples include a body 17 defining a chamber 302 in fluid communication with an inlet and an discharge pressure of the hydraulic couple 300. Various embodiments include a rotating group that includes a rotor 9 to rotate around an axis inside the chamber 302. In various embodiments, the rotor defines a first slot 304 extending parallel to the axis along an exterior of the rotor and opening to the chamber, and a second slot opposite the first and opening to the chamber, the rotor further defining a retainer passage in fluid communication with the first slot with a first vane 7 disposed in the first slot and a second vane 7 disposed in the second slot. Various embodiments include a hydraulically controlled retainer disposed in the retainer passage to retain the first vane in a retracted vane mode of operation and to release the first vane in a vane extended mode of operation in which the first vane and the second vane extend to meet the body to hydraulically work fluid when the first vane and the second vane are moved with respect to the body. In various examples, a pump motor output shaft 11 is propelled in the vane extended mode of operation.

Various embodiments include a coupling housing 1. Some examples include two end bodies 60 and a sleeve 62. Some sealed examples include rotary seals 5 to retain the fluid. In various examples, the port 2 allows oil into and out of the housing 1. In some examples, fluid is to flow to and from a separate reservoir. Alternatively, some examples use a large housing that accommodates enough fluid for operation and cooling. The couple 300 is not limited to application in which the housing is used 1 to retain fluid.

In some examples, port 4 is to engage and disengage the coupling 300 to drive by restraining and releasing the vanes 7. In some examples, port 4 connects through passage P1 via bushing 8 into the rotor 9. In some examples, this allows the vanes 7 to be either restrained or released, such as by moving retainers 71, including wide portions 70 and narrow portions 58, to move a ball 52 through a passage 54 at least partially into a detent 50 to retain a vane 7. One example of vane retraction or release is set forth in US Patent Application Publication No. 2006/0133946, commonly assigned and incorporated herein by reference. Release of the vanes will result in the operation of the coupling that will try to operate as a hydraulic pump.

In some examples, port 4 is to engage and disengage the coupling 300 to drive by restraining and releasing the vanes 7. In some examples, port 4 connects through passage P1 via bushing 8 into the rotor 9. In some examples, this allows the vanes 7 to be either restrained or released. One example of vane retraction or release is set forth in US Patent Application Publication No. 2006/0133946, commonly assigned and incorporated herein by reference. Release of the vanes will result in the operation of the coupling that will try to operate as a hydraulic pump.

In various embodiments, the drive shaft 10 is connected to the rotor 9. In some examples, the drive shaft 10 rotates inside bearings 12, 15 and bushing 8. The drive shaft is configured for connection to a power source such as an electric motor or diesel engine or other in some embodiments. The output shaft 11 rotates inside bearings 13, 14 and bushing 16. Bearing applications can optionally be substituted with bushings, and vice versa. Shaft 11 is connected to a pump coupling ring 17, in some embodiments. Some of these embodiments couple the shaft 11 to wear plates 18. Further embodiments couple the shaft 11 to a thrust plate 19. In some examples, the thrust plate 19 retains the bearing 15. Some examples include a needle roller bearing 14 to add alignment and stability to the assembly. Some examples retain parts with fasteners such as screws into one assembly. In some examples, housing 20 and nut 21 hold the assembly together to resist high pressure forces from oil in operation urging the assembly apart.

In one mode of operation, the couple 300 releases vanes 7 on the spinning shaft resulting in the vanes 7 working a fluid to pump fluid. However, fluid escape from a pump chamber is resisted, such as by forcing the fluid against a relief valve calibrated to a predetermined pressure such as a high pressure. It should be noted that since little pumping occurs, part wear is less of a concern than in a vane pump. In some examples, resistance to input energy is transmitted to an output shaft 11. In some examples, the energy supplied is equal to, or substantially equal to in the case of some leakage, the pressure of the oil and the displacement of the ring. In this configuration, torque=pressure*displacement/2*Pi.

Port 3 in some examples provides remote control of a safety pressure relief valve, such as one positioned in bore 6. Referring to FIG. 5, control of pressure in the couple 300 is effected by controlling the balanced piston 21 situated in chamber 6. In various examples, the balance piston 21 prevents uncontrolled free flow of fluid from one or more pump chambers. In some examples, piston 21 is held by spring 22, but the present subject matter is not so limited.

In some examples, to resist the escape of the oil from the coupling, pressure is placed on both ends of piston 21 via port 24 and orifice 25. Such a configuration disposes a small force on the spring to retain the spool in place, closing off oil escaping from the chamber 6 to drain 23. In some examples, remote control of the pressure via passage P2 allows adjustable pressure control or venting/unloading of the piston 21. Other controls are possible. In some examples, by the oil force pushing spool 21 against spring 22, the system allows fluid to escape from port 24 to drain port 23. In some examples, port 23 is at a lower pressure to provide suction. In some examples, the remote pressure control is adjustable up to 2000 pounds per square inch (13.8 MPa). In some examples, the remote pressure control is provided via a 0.75 millimeter orifice.

In various examples, the input drive shaft 10 converts energy into a hydraulic force that is resisted by the forces on shaft 11. This hydraulic force is generated from the fluid trapped by the vanes working the fluid against the rotor contained by the ring, pressure plates and thrust plates causing shaft 11 to rotate.

The present subject matter provides a compact couple. In some examples, a 100 horsepower coupling has a diameter nominally of 6 inches (15.2 cm), which is smaller than a comparable plate of a clutch or low pressure fluid coupling such as a torque converter. The present subject matter does not suffer from clutch burn out. At stall, the coupling is able to discharge over a safety pressure relief valve preventing “burn-out” or damage to machines coupled to one or both of the input and the out. The present embodiments are efficient as the incorporate selected manufacturing tolerances that result in efficiencies higher than conventional fluid couplings such as a torque converter that require loose engineering tolerances for reliability.

FIG. 7 is a schematic of a hydraulic couple 700 including a cross-section view of a rotating group including pins to extend and retract vanes, according to some examples. A rotating group 705 includes working surfaces 706 (e.g., the illustrated vanes) that are aided by a fluid pressure assist signal 704 to extend away from the rotating group to meet a body coupled to the output 703. The fluid pressure assist can supply all of the force needed to extend the working surfaces 706, or a portion, with a remainder supplied by an inertial force experienced during high speed rotation of the input 702. In some examples, pin 708 is coupled to or against an inner side of the working surface 706 to urge the working surface 706 against a body coupled to an output shaft 703. In various embodiments, an inlet signal 712 is added to control the extraction or retraction of an retainer to lock one or more working surfaces 706 in a retracted position, or to unlock the retainers so that they can extend.

Some examples include a valve 714 to control pressurization of one or more assist signals 704 to extend pins 708. In the illustrated mode, the valve is adjusted to depressurize the assist signal 704, such as through leakage or direction to a drain, such that the working surfaces are be retracted and locked with and inlet signal 712. In a second mode, the valve 714 is adjusted to depressurize the inlet signal 712 such as through leakage or a drain, and to use an assist pressure source 716 to pressurize an assist signal 704 to press fluid against a pin 708 to urge the working surface 706 outward to meet a body coupled to output shaft 703 thereby urging the working surface 706 to work a fluid disposed between the rotating group 705 and the body.

FIG. 8A is a perspective view of a hydraulic couple with a geared body, according to some examples. FIG. 8B is a cross section taken along line 8B-8B in FIG. 8A. In various examples, rotation of an input 802 can be arrested by extending working surfaces 806 to work hydraulic fluid against a body 804 that has a surface 807, such as a geared surface, to output power via the surface 807. In the illustrated example, the surface 807 includes gears that interface with another gear surface 809 to rotate the gear surface 809 to turn the output 803.

The gear system 800 is useful in a number of applications. For example, in one application, the input 802 is fixed to an engine to rotate while the engine rotates. The output 803 is optionally coupled to a supercharger to rotate rotators of the supercharger. In various examples, providing a pilot signal to allow the working surfaces 806 to work a hydraulic fluid against the body 804 causes a hydraulic resistance between the two, resulting in rotation of the body 804 in synchrony with the surface 809 to turn the output 803. In this manner, the supercharger can be activated and deactivated with the provision of a pilot signal. Devices such as a valve are used to switch to provide intake air while the supercharger is deactivated in various examples.

Accordingly, one benefit is that the gear system 800 can be activated and deactivated. In moments when the gears are not used, such as in automotive transmission embodiments in which only some gears are used at some times, gear rotation can be substantially slowed or stopped, which can improve efficiency by reducing or eliminating windage losses attributable to the rotation of the gear system 800 such as in an oil bath.

FIG. 9 is a table showing experimental figures related to a first operating condition. The table illustrates the power required to drive a fan using a gear pump to gear motor topology, using a pressure compensated piston pump to gear motor topology and using embodiments of a coupling as disclosed herein. In some of these examples, an input shaft is coupled to rotating member of a machine such as a crankshaft, and when a signal is provided, retainers release working surfaces such as vanes so that they can work fluid to lock the couple to turn the output shaft to turn a fan blade. The gear pump/gear motor design shows that at full speed, a large amount of power is used due in part to inefficiency. It should also be noted that the system has to be sized to operate all the time, thereby wasting power when fan cooling is not needed. In FIG. 10, the performance of the three topologies are illustrated at half fan speed. Such a condition is possible by regulating the pressure supplied to the couple so that the pressure causes the couple to act as a motor or a pump, in essence rotating the fan attached to the output faster or slower than the rotation of input. The experimental results show that the coupling embodiment is nearly as efficient as the piston embodiment. In FIG. 11, the coupling embodiment is more efficient than the other topologies, due to the improvements discussed herein.

The present subject matter benefits from precise control. In some embodiments, programmable torque settings effected by adjustment of the pressure relief setting result in a predetermined stall points. Such a programmable stall point can be either fixed or remotely by associating the relief valve setting with a remote conventional override relief valve. A further benefit is controlled acceleration or deceleration by varying relief valve settings to match desired maximum torques. In such embodiments, start and stop torques can be reduced to limit high peak torque levels that can damage machinery.

FIG. 12 illustrates a torque amplifier in a couple disengaged of operation, according to some embodiments. Various embodiments include a torque source 1202. The torque source can be any source including, but not limited to, engines such as diesel engines, and electric motors. In some examples, the torque source is a variable speed torque source that is intended to run at different speeds in operation. Examples include diesel engines used to move vehicles such as over the road trucks, off road vehicles, and trains. In additional embodiments, the torque source 1202 is intended to run at a constant speed in operation, such as an industrial induction motor.

Various embodiments include a hydraulic couple 1204 to couple the torque source 1202 to powertrain 1206. One example of a hydraulic couple is illustrated in FIGS. 25-27, but the present subject matter is not so limited and extends to other hydraulic couples disclosed herein. As disclosed herein, the hydraulic couple 1204 includes retainers to retain working surfaces that would, in an unretained mode, work 1205 hydraulic fluid through the couple. In various examples, a pilot signal 1203 is used to control the retainers. The system 1200 includes hydraulic pump motor 1208 such as a digitally controlled piston pump. The pump motor 1208 can be controlled by various methods including, but not limited to, electronically, pressure compensated, lever, or digitally. The pump 1208 includes an output shaft 1210 coupled to the powertrain 1206, the hydraulic pump including a pump motor inlet 1212 in fluid communication with the discharge pressure 1214 of the hydraulic couple 1204, the pump motor 1208 to receive fluid 1216 from the discharge pressure 1214 of the hydraulic couple 1204 to propel the output shaft 1210.

Various examples include a valve 1218 to control operation of the system 1200. An optional accumulator 1220 can store pressurized fluid. An optional shuttle valve 1222 ensures one-way flow of the fluid 1216 in some examples. Some examples include a reservoir to store fluid. A drain 1226 optionally returns to the reservoir 1224 or to another fluid storage device.

In various examples, the powertrain 1206 includes a transmission 1228. There are several benefits of the system 1200 as it relates to transmissions. In FIG. 12, the couple 1204 is configured to allow the input 1202 to spin with respect to the output shaft 1207. This is equivalent to a neutral condition for the vehicle. The pump 1208 can be stroked on slightly or fully in this condition; the degree of stroke is inconsequential as there is little inlet pressure.

FIG. 13 illustrates a torque amplifier in a driving mode of operation, according to some embodiments. The illustrated mode of operation correlates to a steady state driving condition. Torque to the input shaft 1202 is transmitted to the output shaft 1207 with few or no losses; the couple 1204 effectively works as a mechanical shaft. The relief valve 1230 allows the couple 1204 to slip should a problem occur, in a manner that a clutch might slip. In additional embodiments, the relief valve 1230 is used to control the torque output magnitude of the couple 1204.

In arriving at the state illustrated in FIG. 13, a number of beneficial operations occur. In some examples, before a first gear is selected, a torque source 1202 such as an engine is spinning such as at 1500 rpm. As the first gear is selected, such as via positioning the transmission 1228 into a first gear, the hydraulic couple releases working surfaces such as vanes so that the hydraulic couple 1204 pumps against a fluid 1216. Provided the valve 1218 is so adjusted, the hydraulic couple 1204 begins to pump fluid 1216 to the pump 1208. The pump receives fluid 1208 and strokes on gradually to begin to move the powertrain 1228. After a steady state is reached, if a boost of torque is required, the system can again introduce hydraulic motor torque through 1210 on top of the torque the engine produces through 1207.

In some examples, after a steady state driving mode is reached, the valve 1218 selects to resist pumping by the couple 1204. The couple 1204 essentially locks except for any leakage, and the pump 1208 strokes off. In this mode, the input 1202 is locked to the output 1207 and thereby to the transmission 1228 and the inefficiencies of the hydraulic system are substantially reduced or eliminated. Further, the risk of damaging the motor pump 1208 is reduced.

Accordingly, several benefits are realized including reducing peak transient forces experienced by the transmission 1228. The peak transient forces are reduced by the couple 1204 separating the engine from the transmission 1228 and the pump 1208 gradually adding them back to the transmission 1228. Because of the adjustability of the system, the vehicle can operate with a simpler transmission that includes fewer speeds. Such transmissions are less expensive, are easier to repair, are lighter, and because they have less complexity, are less likely to break.

FIG. 14 illustrates a torque amplifier in a regenerative braking mode of operation, according to some embodiments. In this embodiment, the couple can be engaged or disengaged. The pump motor 1208 is stroked to a pumping mode to direct fluid generated during vehicle deceleration into the accumulator 1220. If the accumulator is full, the pump can be used to force fluid over a relief valve, or it can optionally be stroked off of pumping. In various examples, wheel brakes are used to assist in stop. In some additional examples, the couple 1204 is engaged to allow for engine braking.

FIG. 15 illustrates a torque amplifier in a regenerative braking mode of operation, according to some embodiments. In this example, energy stored in the accumulator 1220, such as energy stored during deceleration of the vehicle, is used to accelerate the vehicle. The valve 1218 is adjusted and the pump motor is stroked to a motor mode to propel the vehicle. In this mode, the coupling 1204 is engaged and pumps fluid until the resistance from the fluid 1216 reaches a magnitude to substantially lock the couple 1204. The fluid 1216 can reach such a pressure through adjustment of the valve 1218. The fluid 1216 can additionally reach such a pressure when the pump motor 1208 experiences a high resistance to propulsion.

FIG. 16 illustrates a torque amplifier in a first mode of operation, according to some embodiments. This embodiment illustrates an optional gear set 1250 to alter the rotation ratio between the torque source 1202 and the transmission 1228 so that it's a ratio other than 1:1.

FIG. 17 illustrates a vehicle including a torque amplifier, according to some examples. The illustration represents one possible configuration, and others are possible. By positioning the hydraulic couple 1204 before the transmission, more operational modes are possible than with configurations in which a hydraulic pump or pump motor is downstream 1240, such as when the pump motor is between the transmission 1228 and a differential for an axle.

One benefit of the system 1200 is that the fluid 1216 can optionally be used to drive accessories such as dump boxes. This is an improvement over designs in which a pump 1208 is between a transmission and the remainder of the powertrain because in those systems, the vehicle would have to be moving in order to provide pumped fluid to drive an accessory. In the present examples, a valve can allow the couple to pump fluid to drive an accessory. Another benefit of the system 1200 is that in a steady state driving mode the system does not emit hydraulic noise, sparing the operator from listening to what is often regarded as an unpleasant noise.

FIG. 18 illustrates a load ultimately driven by an electrical motor, according to some embodiments. The system 1800 includes grid power 1802 that is used to power an motor 1804 such as an AC induction motor. The motor 1804 is coupled to the hydraulic couple 1806 to provide an input torque. As discussed herein, the hydraulic couple 1806 is to cooperate with the pump 1808 to gradually introduce torque to the powertrain 1810, thereby working the load 1812. Such a configuration reduces the complexity of the system 1800 when compared to designs using a gearbox or a larger, more expensive multi-speed motor.

FIG. 19A is a perspective view of a vane including a roller tip, according to an example. FIG. 19B is a bottom view of FIG. 19A. FIG. 19C is a top view of FIG. 19A. FIG. 19D is a front view of FIG. 19A. FIG. 19E is a side view of FIG. 19A. FIG. 19F is a perspective view of FIG. 19B, cross-sectioned at line 19F-19F. FIG. 19G is a bottom view of FIG. 19F. A vane 1902 includes a journal 1903 in which a vane 1904 is disposed. In some optional configurations, a port 1906 extends from the bottom of the vane to the journal 1903 to provide hydraulic fluid to the vane, such as to lubricate it, to balance it in a vane pump and/or to provide a hydrodynamic bearing to support the vane 1904.

The present detailed description refers to subject matter in the accompanying drawings that show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The present detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined only by the appended claims, along with the full scope of legal equivalents to which such claims are entitled.

This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of legal equivalents to which such claims are entitled. 

1.-15. (canceled)
 16. A hydraulically controllable coupling, comprising: an input shaft coupled to rotate one of a body defining a chamber, the body in fluid communication with an inlet, and a rotating group disposed in the chamber; an output shaft coupled to rotate the other of the body and the rotating group, wherein the rotating group comprises: a rotor to rotate around an axis inside the chamber, with the rotor defining a first slot extending parallel to the axis along an exterior of the rotor and opening to the chamber, and a second slot opposite the first and opening to the chamber, the rotor further defining a retainer passage in fluid communication with the first slot; a first vane disposed in the first slot; a second vane disposed in the second slot; and a hydraulically controlled retainer disposed in the retainer passage to retain the first vane in a retracted vane mode of operation and to release the first vane in a vane extended mode of operation in which the first vane and the second vane extend to meet the body to hydraulically work fluid when the first vane and the second vane are moved with respect to the body; and wherein the input and the output are coupled to rotate together in the vane extended mode of operation, and the input and output are free to rotate with respect to one another in the vane retracted mode of operation.
 17. The hydraulically controllable coupling of claim 16, comprising: a torque producer coupled to the input shaft; a fan coupled to the output shaft; and a hydraulic pump motor including an output shaft coupled to the fan, the hydraulic pump motor including a pump motor inlet in fluid communication with a discharge pressure of the hydraulic couple, the pump motor to receive fluid from the inlet of the hydraulic couple to propel the output shaft in the vane extended mode of operation.
 18. The hydraulically controllable coupling of claim 16, comprising: a torque producer coupled to the input shaft; a powertrain coupled to the output shaft; and a hydraulic pump motor including an output shaft coupled to the powertrain, the hydraulic pump motor including a pump motor inlet in fluid communication with a discharge pressure of the hydraulic couple, the pump motor to receive fluid from the inlet of the hydraulic couple to propel the output shaft in the vane extended mode of operation.
 19. The hydraulically controllable coupling of claim 18, wherein the torque producer is one of an internal combustion engine and an electrical motor.
 20. The hydraulically controllable coupling of claim 18, wherein the first vane is a roller tipped vane.
 21. The hydraulically controllable coupling of claim 16, wherein an outlet of the body is in fluid communication with a relief valve.
 22. The hydraulically controllable coupling of claim 21, wherein and the relief valve is associated with an overload torque to allow the rotating group to spin with respect to the body in the vane extended mode of operation and pump oil over the relief valve.
 23. The hydraulically controllable coupling of claim 16, wherein the retainer is a ball.
 24. A method, comprising: coupling an input of a vane pump to a torque producer, and an output to a load; adjusting a pilot signal pressure to the rotating group of the vane pump to lock vanes in a vane retracted mode of operation such that the input of a vane pump, coupled to one of a body and rotor of the vane pump, is free to spin with respect to the output of the vane pump and the other of the body and the rotor of the vane pump; and adjusting the pilot signal pressure to lock vanes in a vane extended mode of operation such that the input of a vane pump drives the output of the vane pump and the other of the body and the rotor of the vane pump.
 25. The method of claim 24, wherein the load includes a fan.
 26. The method of claim 25, comprising powering the vane pump with the fan.
 27. The method of claim 24, including pumping oil with the rotating group in response to overloading vane pump.
 28. The method of claim 27, wherein pumping oil includes pumping oil over a relief valve.
 29. The method of claim 28, comprising selecting the relief valve to select an overload torque associated with overloading the vane pump.
 30. The method of claim 24, comprising storing hydraulic pressure in an accumulator in a regenerative braking mode in which the vane pump is in the extended mode of operation, in which the output of the vane pump is driven by the load.
 31. The method of claim 30, comprising bleeding pressure generated by the vane pump over a relief valve when the accumulator is full.
 32. The method of claim 30, comprising driving, after the regenerative braking mode, the load with the vane pump using hydraulic pressure stored in the accumulator.
 33. The method of claim 24, comprising driving the load in the vane extended mode, such that a load torque includes torque from the torque producer and torque from the vane pump.
 34. The method of claim 24, comprising driving the torque producer in the vane extended mode by producing torque with the load.
 35. The method of claim 34, wherein producing torque with the load includes rotating a fan. 